Grade 12 Chemistry: Percentage Yield
This worksheet focuses on calculating and understanding percentage yield in chemical reactions for Grade 12 Chemistry students.
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Grade 12 Chemistry: Percentage Yield
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Read each question carefully and provide detailed answers. Show all your work for calculation problems.
1. The theoretical yield is the maximum amount of product that can be formed from a given amount of .
2. The yield is the amount of product actually obtained from a reaction.
3. Percentage yield is calculated by dividing the actual yield by the theoretical yield and multiplying by .
1. Explain why the actual yield in a chemical reaction is almost always less than the theoretical yield. Provide at least two reasons.
1. In the reaction 2H₂ + O₂ → 2H₂O, if 10.0 g of H₂ reacts completely, and 80.0 g of H₂O is produced, what is the theoretical yield of H₂O?
45.0 g
90.0 g
80.0 g
10.0 g
1. In an experiment, 25.0 g of calcium carbonate (CaCO₃) is heated to produce calcium oxide (CaO) and carbon dioxide (CO₂). If 12.0 g of CaO is actually produced, what is the percentage yield of CaO? (Molar mass of CaCO₃ = 100.09 g/mol, CaO = 56.08 g/mol)
2. Consider the reaction: 2Al + 3Cl₂ → 2AlCl₃. If 54.0 g of aluminum (Al) reacts with excess chlorine (Cl₂), and 150.0 g of aluminum chloride (AlCl₃) is collected, calculate the percentage yield. (Molar mass of Al = 26.98 g/mol, AlCl₃ = 133.34 g/mol)
1. A percentage yield greater than 100% is impossible under normal laboratory conditions.
True
False
2. Impurities in reactants can lead to an artificially high actual yield.
True
False